1. Field of the Invention
This invention relates to barometric damper apparatus, or self-closing louver apparatus useful particularly in the Heating, Ventilating, and Air Conditioning (HVAC) industry and, more particularly, to barometric damper apparatus that may be interchangeably used for both side draft and down draft applications without structural changes.
2. Description of the Prior Art
Barometric damper apparatus comprises louver elements which open and close automatically in response to a flow of air. When there is an air flow, as an air moving device such as a fan or blower is operating, the barometric damper apparatus, or the louvers open to allow the flow of air through the louvers. When the blower is turned off, the flow of air ceases and the barometric damper apparatus, or the plurality of louvers, close. The opening and closing is in response to the flow of air, and specifically to the weight and balance and pivoting action of the damper or louver elements. Typically, the damper elements, or louvers, pivot between the "top" and "bottom" edges. That is, the louvers are balanced in such a manner that a positive or negative flow of air will cause the dampers to pivot to a generally parallel orientation when there is a flow of air against, and between, the louvers of the damper. When the flow of air ceases, or reverses, the elements pivot by gravity to close, thus preventing air from traveling back through the apparatus in the opposite direction to the desired air flow.
In prior art, there are required two different designs for barometric dampers, depending on their particular placement. There is a barometric damper of a particular weight design required for a side draft application, and a different weight designed barometric damper for a down draft application. The two barometric damper designs of the prior art are not interchangeable. The apparatus of the present invention is interchangeable.
Since two different designs of barometric dampers are required in the field, or at a job site, according to a particular installation, it is obvious that an inventory must be kept for both types of damper. When an order comes in for a particular damper, only that type of damper design must be sent to the job site. Unfortunately, confusion is inevitable, and it has been suggested that there is probably an error rate of as much as fifteen percent (15%) of all installations in the ordering of the barometric damper apparatus. Naturally, this leads to much lost time on both the part of the installer and the part of the wholesaler or supplier. The required paperwork is obviously also affected and represents financial losses.
A primary difference between down draft and side draft barometric damper designs is in the weight, or in the weight distribution, of the louver blade elements. The weight involved in the down draft elements is greater than that of the side draft elements because the down draft elements must close against the force of gravity for a substantial amount of weight. That is, in returning to a generally horizontal alignment in the closed position, each louver element must pivot against a gravitational force, whereas in the side draft louver elements the pivoting action is generally primarily with the force of gravity.
The apparatus of the present invention overcomes the deficiencies of the prior art by providing a barometric damper apparatus which is usable, and thus interchangeable for both down draft and side draft applications without structural changes to the apparatus.